Regression Part 2
POLS 3316: Statistics for Political Scientists
2023-11-14
Review
More on some terms that have been used occasionally: fit, fitted, predicted, residual, predictors, estimates (plus estimator and estimand)
Regression with two or more Xs: multiple linear regression
Interpreting Regression Results
\(y = \alpha + \beta X + \epsilon\)
During the lecture on causation, I said that causes aren’t simple - there are often multiple causes
So how do we analyze 2 (or 3 or 20) explanatory (X) variables?
With OLS regression.
When we add a second X, we add a new axis so now we don’t have a line, we have the 3d equivalent::
Multiple Regression plane
We can’t really visualize more than two Xes geometrically, but the idea is the same.
Study shows probability of getting Covid for mask wearers and non-mask wearers
Author: Tom Hanna
Website: tomhanna.me
License: This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
POLS3316, Fall 2023, Instructor: Tom Hanna